[ClusterLabs] Antw: Re: Antw: Re: Rename option group resource id with pcs

[Ulrich Windl]

>>> Kristoffer Grönlund <kgronlund at suse.com> schrieb am 11.04.2017 um 15:25 in
Nachricht <87o9w3krf6.fsf at suse.com>:
> Ulrich Windl <Ulrich.Windl at rz.uni-regensburg.de> writes:
> 
>>>>> Dejan Muhamedagic <dejanmm at fastmail.fm> schrieb am 11.04.2017 um 11:43
in
>> Nachricht <20170411094352.GD8414 at tuttle.homenet>:
>>> Hi,
>>> 
>>> On Tue, Apr 11, 2017 at 10:50:56AM +0200, Tomas Jelinek wrote:
>>>> Dne 11.4.2017 v 08:53 SAYED, MAJID ALI SYED AMJAD ALI napsal(a):
>>>> >Hello,
>>>> >
>>>> >Is there any option in pcs to rename group resource id?
>>>> >
>>>> 
>>>> Hi,
>>>> 
>>>> No, there is not.
>>>> 
>>>> Pacemaker doesn't really cover the concept of renaming a resource.
>>> 
>>> Perhaps you can check how crmsh does resource rename. It's not
>>> impossible, but can be rather involved if there are other objects
>>> (e.g. constraints) referencing the resource. Also, crmsh will
>>> refuse to rename the resource if it's running.
>>
>> The real problem in pacemaker (as resources are created now) is that the 
> "IDs" have too much semantic, i.e. most are derived from the resource name 
> (while lacking a name attribute or element), and some required elements are

> IDs are accessed by ID, and not by name.
>>
>> Examples:
>>     <cluster_property_set id="cib-bootstrap-options">
>>       <nvpair id="cib-bootstrap-options-dc-version" name="dc-version" 
> value="1.1
>> .12-f47ea56"/>
>>
>> A <clone>s and <primitive>s have no name, but only an ID (it seems).
>>
>>           <op id="prm_DLM-start-0" interval="0" name="start"
timeout="90"/>
>>
>> This is redundant: As the <op> is part of a resource (by XML structure)
it's 
> unneccessary to put the name of the resource into the ID of the operation.
>>
>> It all looks like a kind of abuse of XML IMHO.I think the next CIB format 
> should be able to handle IDs that are free of semantics other than to denote

> (relatively unique) identity. That is: It should be OK to assign IDs like 
> "i1", "i2", "i3", ... and besides from an IDREF the elements should be 
> accessed by structure and/or name.
>>
>> (If the ID should be the primary identification feature, flatten all 
> structure and drop all (redundant) names.)
> 
> The abuse of ids in the pacemaker schema is a pet peeve of mine; it
> would be better to only have ids for nodes where it makes sense: Naming
> resources, for example (though I would prefer human-friendly names
> rather than ids with loosely defined restrictions). References to
> individual XML nodes can be done via XPATH rather than having to assign
> ids to every single node in the tree.
> 
> Of course, changing it at this point is probably not worth the trouble.

Maybe in the next generation called "reanimator" ;-)
(From the history of names forcussing on death more strongly, the obvious
sequence for future products will be (starting from heartbeat, pacemaker):,
reanimator, frankenstein (after that it'll be difficult to find names I'm
afraid))
Sorry, I couldn't resist...

Ulrich
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